I have a 99 a4 quattro 4cyl 1.8t. I left for a 3 week trip and had my car sit at my house. I asked a friend to go over once a week and drive it around town but of course why would that get done. So upon my return home my battery is completely dead... no big deal charged it and started the car. Upon starting it, it would stall. I can start the vehicle and keep it rev'd up above 1k rpm. I did manage to get it to idle after toying with the gas for a few minutes. It would idle at just under 500 rpm and would be a little shaky. I went and picked up some sea foam and fresh gas, managed to get it out to the high way and attempt to open her up. While driving, i could not keep the throttle at a steady spot with out it jumping which seemed to be in and out of gear but i did not physically have to put it back in gear... I drove for a good 45 minutes and there was no sign of improvement.. any suggestions??

 

Check for fault codes. If you don't have an OBDII scanner, you can go to a place like Advance Auto or Autozone and have them scan your car.

 

I will head over to Adv Auto tonight after work and see what we can come up with. .... Just kinda thinking about things, would bad spark plugs cause this? I just had them replaced maybe 3 months ago though. Also we did have some bad storms while i was away, by any chance if the computer were to get wet, would it possibly cause these problems? Just spit balling here..

 

Had the same problem. In my case a throttle body alignment using VAG-COM solved it (the ECU was without power long enough to lose the settings). Note that the key in ignition for 90 seconds TBA method didn't work for me.

 

This could definitely do it.

To ensure the greatest chance of a throttle body alignment occurring (without VAG-COM), I would suggest following this list:
-unplug battery for maybe 5-10mins
-plug battery in, right away hook up a charger to the battery
-put the key in, turn to ON position (but don't start car)
-wait a few minutes, turn key OFF
-go ahead and start the car

 

You usually need vag com when it gets to the point of stalling. When i replaced ecus it did the same thing and the other method had no affect ( I tried atleast 10 times). So i got vagcom light license and it fixed it right away.

 

I'm trying the disconnect method first for the hell of it. I called the Audi Dealer and they said before i bring it in for the vag com procedure to have someone run and clear the codes and try that... I dont see why places can run and clear my codes if they dont have a vag com? I'm very much not a mechanical person so this is all jibberish to me, but it is making sense to the people i talk to. Thank you all for the suggestions, it has pushed me in the direction i need to go. Thanks!!

 

You can actually clear codes with a generic OBDII scanner from a parts store. Though it's my understanding that they typically won't let you clear codes with their scanners. In any case, the Audi dealer is right, you can't do a throttle body adaptation with any fault codes, and this is the exact reason why I suggested you unplug the battery for at least a few minutes (it resets the ECU).

 

Sorry for not replying in a few days, been busy setting up school and all that jazz.... So far no luck, I have set an appointment up with the dealership for tomorrow. I have been trying to find somebody with a vag-com closer to me because the dealer is over a hour away, but living in the middle of nowhere its like finding a needle in a hay stack. Hopefully the dealers can get her going again with minimal cost, but i doubt it.